Greenland's ice sheet is melting at a rate that is seven times faster than in the 1990s, which could lead to coastal areas around the world with populations in the hundreds of millions facing flooding.

The scale and speed of Greenland's ice loss is much higher than was predicted by the Intergovernmental Panel on Climate Change (IPCC).  It means the IPCC's earlier prediction of a sea rise of 60 centimeters by the year 2100 will actually be 7 centimeters higher - 67 centimeters.  That additional water flooding into low lying coastal areas will impact 400 million people,not 360 million as earlier predicted.

The new data appears in a report published on Tuesday in the journal Nature.  The conclusion co-signed by 96 polar scientists came after they studied 26 separate surveys of Greenland from 1992 to 2018, with data from 11 different satellites and comparisons of volume, flow, and gravity compiled by the experts in the UK, NASA, and the European Space Agency.

"These are not unlikely events or small impacts," said Professor Andrew Shepherd, of the University of Leeds, one of the lead authors.  "(These impacts) are happening and will be devastating for coastal communities."  

Greenland has lost 3.8 trillion tons of ice since 1992.  The rate of ice loss has risen from 33 billion tons a year in the 1990s to 254 billion tons a year in the past decade.